I agree - BUT... He did ask and receive permission to send them a letter. If a Mormon or Catholic LEO asked if he could send me a letter about his religion I would politely thank him for his offer, tell him I am quite happy as a Southern Baptist and not interested in his offer.
Given the fact that he is (was?) a Law Enforcement Officer, his professional status alone makes it inappropriate to even ask for such permission and given the potential for intimidating circumstances in a traffic stop, the permission is in itself rather worthless from a legal standpoint.
"Executed Under Duress" means something, even in today's twisted world.